Biocompatible and biodegradable natural disperse dyes for dyeing polyester fabrics

Abstract

The present invention is directed to a biocompatible and biodegradable natural disperse dye for dyeing polyester fabrics which is dispersed in water and derived from green plants. The disperse dye contains as the active dye compound an acid bewchlorophyllin derivative such as acid form Mg-chlorophyllin or acid form Cu-chlorophyllin. The disperse dye of the present invention can be used for the dyeing of polyester fabrics by traditional methods in concentrations ranging from 0.01% to 20% on weight of fibers (OWF), thus providing a dyed fabric with good color strength and good fastness to light, washing and rubbing, under conditions of dye exhaustion of greater than 90%.

Description

REFERENCE TO RELATED PUBLICATIONS[0001]This application is a Continuation-in-Part of U.S. patent application Ser. No. 15 / 125,171, filed on Sep. 11, 2016, which is a National Phase filing under 35 U.S.C. 371 of PCT Patent Application No. PCT / IL2015 / 050305 filed on Mar. 24, 2015, which claims the benefit of priority of U.S. Provisional Patent Application Nos. 61 / 969,879 and 62 / 001,651, filed on Mar. 25, 2014 and May 22, 2014, respectively. The contents of the above applications are all incorporated by reference as if fully set forth herein in their entirety.FIELD OF THE INVENTION[0002]This invention relates in general to natural disperse dyes. In particular, it relates to disperse dyes derived from green plants such as duckweed or parts thereof, which dyes are particularly well-suited for dyeing polyester fabrics.BACKGROUND OF THE INVENTION[0003]The quality of textile materials is determined by the properties of fibers used and the finishing applied to them. Finishing represents a sum...

AI Technical Summary

Benefits of technology

[0039]It is a further object of this invention to disclose such a method, wherein said step of extracting is preceded by a step of drying said green plant biomass. In some preferred embodiments of the invention, said step of drying comprises drying said green plant biomass in darkness. In some preferred embodiments of the invention, said step of drying comprises drying said green plant biomass at a temperature not exceeding 50° C. In some more preferred embodiments of the invention, said step of drying comprises drying said green plant biomass at a temperature not exceeding 45° C. In some particularly preferred embodiments of the invention, said step of drying comprises drying said green plant biomass at a temperature not exceeding 40° C. In some embodiments of the invention, said step of drying comprises drying said green plant biomass until the moisture content is between 10 and 15% by weight. In some other embodiments of the invention, said step of drying comprises drying said green plant biomass until the moisture content is between 5 and 10% by weight. In yet other embodiments of the invention, said step of drying comprises drying said green plant biomass until the moisture content is between 2 and 4% by weight.

[0040]It is a further object of this invention to disclose a method for preparing a chlorophyll-based disperse dye as defined in any of the above, comprising grinding said green plant biomass at a temperature not exceeding 30° C. prior to said step of extracting. In some embodiments of the invention, said step of grinding comprises grinding said green plant biomass to particles not exceeding 200 μm in diameter. In some preferred embodiments of the invention, said step of grinding comprises grinding said green plant biomass to particles not exceeding 150 μm in diameter. In some more preferred embodiments of the invention, said step of grinding comprises grinding said green plant biomass to particles not exceeding 100 μm in diameter.

Problems solved by technology

The textile dyeing industry, responsible for dyeing various types of fiber, stands out as a particularly significant source of environmental pollution.

In these baths, as previously mentioned, it is estimated that approximately 10-50% of the dyes used in the dyeing process are lost, and end up in the effluent, contaminating the environment with about one million tons of these compounds.

The release of improperly treated textile effluents into the environment can become an important source of problems for human and environmental health.

The major source of dye loss is due to incomplete fixation of the dyes during the textile fiber dyeing step.

In addition to the problem caused by the loss of dye during the dyeing process, in the context of environmental pollution, the textile industry also uses large volumes of water consequently generating large volumes of effluent.

Although they are superior to other categories of synthetic fibers, they cannot be dyed with water soluble dyes.

However, in practice natural chlorophylls are rarely used as colorants for several reasons.

First, when chlorophyll is extracted from plant matter, carotenoids, phospholipids and other oil-soluble substances (called “oleoresin”) are invariably extracted with the chlorophyll, resulting in products lacking a well-defined composition and with variable levels of pigments, which makes subsequent purification steps essential.

Second, endogenous plant enzymes and extraction conditions employed can easily promote chemical modification of the chlorophylls, yielding unattractive brownish-green degradation products like pheophytins and pheophorbides.

Consequently, the production costs considering the mentioned difficulties are very high and therefore a more widespread application of natural chlorophylls as colorants is limited.

Thus, after removal of the solvent used to extract the chlorophyll, the resulting product has an oily character.

Difficulties are encountered in substituting the Mg atom except with a Grignard reagent.

As explained above, for fabrics such as polyesters, water-soluble dyes cannot be used, and the synthetic disperse dyes known in the art for dyeing polyesters tend to be extremely environmentally unfriendly.

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